Cross-cultural research covering multiple languages and cultures involves negotiating conceptual and linguistic challenges. This paper focuses on how researchers working across cultural and linguistic boundaries navigate the research process and negotiate a common understanding of the constructs under study. Working towards intersubjectivity within a cross-cultural research team is essential, as it deepens understanding of one another's contexts and our own. We analyze our own research process, as a cross-cultural team studying elementary school teachers' use of print and digital instructional resources in Finland, Flanders, Sweden, and the U.S. Recorded team conversations served as data to help us explore the way language and culture are intertwined and how these relationships surface when developing research instruments and conducting analysis of the interviews, in which language became a focal point. Challenges emerged particularly within three research aims, namely, naming and describing teaching practices, understanding teachers' relationships with mathematics resources, and defining digital resources in a cross-cultural survey. Our systematic analysis of instances of conceptual and linguistic inequivalence prompted the team to make language explicit and revealed that these instances varied in several ways that had implications for how and whether they might be bridged. Thus, this paper contributes to understanding the methodological impact of using a shared language, acknowledging that researchers' lexicons about mathematics teaching are closely linked to their own cultural knowledge and experience. Therefore, working explicitly across language and culture towards mutual understanding is a necessity and a way to reinforce the validity of research outcomes.